Orange Juice Flavour

I ran across yet another news item about processed food the other day, and decided to find out a bit more about what was behind it.

For those who didn't click the link above: I'm not talking about twinkies, I'm talking about orange juice. Because make no mistake about it, unless you cut and juice oranges yourself, the orange juice you drink is chemically processed. It has to be—fresh squeezed orange juice goes bad on a time scale of a couple of days even with refrigeration. (Apparently you can buy unpasteurized OJ, but it has a "use by" date about 2-3 days after the oranges are juiced at the processing plant. I don't recall seeing it for sale in Canada, which is about a 24-hr drive nonstop from the orange groves... Doesn't mean it isn't here, only that I haven't seen it.)

I found several descriptions of how orange juice concentrate is made, but fewer of how "not from concentrate" is made. What I've been able to glean from various sources is that the fresh orange juice is pasteurized both to kill any microbial contaminants and to stabilize the "cloud" (the opaque part of the juice that holds most of the flavour compounds), and de-aerated to both make packaging easier and to protect the vitamin C from degradation by dissolved oxygen. Then, flavour compounds removed in de-aeration and pasteurization are added back in.

There have been quite a few studies published about what chemicals present in oranges cause that delicious OJ flavour and how and when they're lost, but I wasn't able to find anything in the literature (which I have access to today; I saw a few tantalizing sources but they're in books) about which of those are added back in and in what concentrations. It looks to my reading like the de-aeration process allows those flavour compounds to be captured and purified, and this is what makes up the "flavour pack" added back to the processed orange juice to make it taste fresh again.

On looking back at the news item linked at the top of this post, however, the lawsuit is related to false advertising more than anything. The ads imply that the orange juice is squeezed and that's it for processing, when really "not from concentrate" involves a few extra steps. I'm definitely in favour of truth in advertising—how are we supposed to make informed decisions about what we buy if we're misinformed?

The media coverage and blog posts which were polluting my search results while researching this post, on the other hand, seems to be mostly hysteria about what those horrible chemicals are that are added back in to make their OJ tasty again. (Hint: it's the same chemicals lost in processing, which are produced by the orange itself. Because, you know, that's what makes OJ taste like OJ.)